Posts filed under ‘The Two Trains Puzzle’

The Two Trains Puzzle

Two trains are on the same track 100 km apart and each travelling at a speed of 50 km per hour are heading towards each other. A fly, initially on the front of one train, flies at 75 km per hour towards the oncoming train. On reaching it, the fly turns around instantaneously and flies back towards the other train. When it reaches the front of this train, it turns around again instantaneously and flies back towards the first train. How many kilometres will it have travelled before the two trains collide?

+Mousing Around: Another Book and Some Puzzles
+In Code: A Mathematical Journey
+MathWorld: Two Trains Puzzle

August 8, 2010 at 6:09 pm Leave a comment